Supporting and clamping mechanism for drilling machines



W.- T. SEARS. SUPPORTING AND CLAM'PING MECHANISM FOR DRILLING MACHINES.

APPLICATION FILED MML 17', I919.

Patented June 6, 1922.

2 SHEETSSHEET I.

W. T. SEARS. SUPPORTING AND CLAMPING MECHANISM FOR DRILLING MACHINES.

APPLICATION FILED MAR. 17,1919.

PatentedJune 6 1922. 2 SHEETS-SHEET 2.

\I z w .V, w 6 ,2 a 2 M m v Q E Il/I/ A WVEWTO/P I I/MM/ CW A7 ZZWEI I dlfrtd WILLARD 'r. SEARS, or MoN'roLAiR, NEW JERsRY, ASSIGNOR 'ro NILES-BEMiflqgroNn COMPANY, or NEW YORK, N. Y., A CORPORATION or NEw'JRRsEY.

i, eraser.

Specification of Letters Patent.

Patented June 6, 1922.

Application filed March 17, 1919. Serial No. 283,171.

To all whom 2'13 may concern:

Be it known that I, VVILLARD T. SEARS, a

citizen of the United States, residing at Montclair, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Supporting and Clamping Mechanisms for Drilling Machines of which the following is a specifica tion.

The invention relates particularly to a mechanism of the type disclosed in my copending application for supporting and clamping mechanism for drilling machines, Serial No. 229,999 filed April 22nd, 1918. One of the objects of the present invention is to provided an improved clamping mechanism which is positioned so as to have a peculiarly effective action. A further object of the invention is to provide improved column supporting devices. these devices preferably being so arranged as to permit the insertion of a centrally disposed vertical drive shaft when desired. ()ther objects of the invention will be apparent from the following specification and claims.

In the accompanying drawings I have shown the embodiment of the invention which is new deemed preferable, but it will be understood that modifications and substitutions of equivalents may be made within the scope of the patented claims without departing from the spirit of the invention.

Of the drawings:

Fl 1 is an elevational. view of a drilling machine embodying the invention.

Fig. 2 is a longitudinal vertical sectional view through the base at the lower part of the column. this view being on an enlarged scale. i

Fig. 3 is a plan view, partly in section along the. line of Fig. 2.

Fig. 4 is a detail side view of the clamp and associated parts.

Fig. 5 is a detail sectional view taken along the line 55 of Fig. 2.

Fig. 6 is a diagram of the electrical connections.

- Referring to the drawings. 1 and 2 represent the base of the drilling machine. Mounted upon the base for movement about a vertical axis is a column3. Preferably. as indicated in Fig. 3, this column is divided. or formed in two parts 3 3 as shown in my Patent 1,071,590 dated August 26th..

Supported on the column and preferably vertically movable with respect thereto ISJL horizontal arm 4 along which is slidable a saddle 5 carrying a head provided with a rotatable spindle 6. Preferably the arm 4 or a carrying member therefor extends through the column between the two parts 3, 3f thereof and directly supports a gear casing 7 and an electric motor 8. i From the motor 8 power is transmitted through gearing in the casing 7 to the main power shaft 9 extending longitudinally of the arm and thence to the spindle 6. The mechanisms thus far described do not of themselves constitute any part of the present invention and they can be considerably modified as required.

The column 3 preferably is provided with an extension 10 which projects downward into the base parts 2 and 1. This exten sion is engaged by two bearings which serve to hold the column in axially fixed position and which at the same time permit turning movement. ing interposed between the extension 10 and the upper part of the base section 2. At 12 there is a roller bearing interposed be tween the lower end of the extension 10 and a cupped plate 13 secured to the lower base section 1.

For carrying the weight of the column and associated parts during turning movement, 1 provide series of centrally disposed devices. As illustrated, there is an antifriction column support in the form of a ball thrust bearing 14 which rests upon the before mentioned plate 13. Engaging the top race of the ball bearing is a vertical tube 15.. this tube extending through a central aperture in the projection 10 and being freely movable therein. Supported on the top of the tube 1.5 is a coil spring 16 and this coil spring in turn supports a second vertical tube 17. The tube 17 at its top engages a bushing 18-which has threaded engagement with the column.

The spring 16 is sufficiently powerful to carry the entire weight of the column and associated parts when they are rotated. The bottom of the column 3 is provided with a horizontal surface 19 adapted under certain conditions to engage a horizontal surface 20 on the top of the base section 2. In as- At 11 there is a roller bearsembling, the surfaces 19 and 20 will be initially in contact. The bushing 18 is then turned so as to transfer the weight of the column from the base 2 to the vertical tube lTand thence to the spring 16 and the ball bearing 1 The column is thus supported with the surfaces 19 and 20 entirely out of engagement. This construction is similar in principle to that described in my aforesaid application Serial No. 229,999, but is different in certain important respects. One feature of difierence is that the several column-supporting devices are so constructed and arranged as to leave an unobstructed central vertical aperture through the, base and the lower part of the column. Under some circumstances it is desirable to modify the drive mechanism by omitting the electric motor 8 and by substituting a vertical drive shaft. The construction described makes it possible for the vertical drive shaft to be put in place in the central vertical aperture referred to.

The positions and relative weights of the motor and of the arm together with the saddle and drill head are such that under ordinary conditions the resultant center of gravity is approximately at the center of the column and therefore vertically above the ball bearing 14. With the surfaces 19 and 20 out of engagementand with the weight of the parts substantially balanced on the bearing 14, it is possible to swing the column and arm very easily. After the arm has been swung to the desired position the column is clamped by the mechanism to be now described. The clamping mechanism is vertically acting, vim, applies pressure to the col umn downward in opposition to the spring, thus forcing the surface 19 into a direct clamping engagement with the surface 20.

In accordance with the present invention, the clamping mechanism is so located as to act at the same side of the column as that from which the arm 4: projects. The reaction from the drilling operation is upward, and. I secure the maximum of resistance to this reaction by placing the clamping mechanism preferably immediately heneaththe arm and as far as possible from the center of the column.

As illustrated, a bearing bracket 21 is secured to the column at the same side thereof as the arm' and vertically beneath the arm. This bracket is provided with two similar bearings: 22, 22 which carry a rotatable shaft 23. Secured to the shaft between the bearmechanism, as illustrated, is preferably exterior of the column and therefore easily accessible.

The operating mechanism for the clamp preferably includes a solenoid 29. A link 30 connects the movable core of the solenoid with the above mentioned arm 24. Preferably, as shown, this link is divided so as to leave the central part of the column over the bushing 18 UI'lOlJStIHCtGCl. This permits the use of a central vertical power shaft, as before stat-ed. Preferably the bracket 21 carries an abutment 31 and a coil spring 32 is interposed between the abutment 31 and the outer part of the link 30. This spring serves to move the parts outward when permitted by the solenoid.

It Will be seen that when the solenoid is energized the core thereof together with the link 30 are moved. toward the left and the arm 24 and the shaft 23 are turned in the counter-clockwise direction, thus applying upward pressure. to the yoke 27 by means of the eccentrics 25, 25 and the blocks 26, 26. By reason of the engagement of the yoke with the flange 28, the entire column and associated parts are drawn downward, thus forcing the bearing surface 19 into a direct clamping engagement with the bearing surface 20. When these two surfaces are engaged'the column 3 is very firmly supported so as to resist the reaction resulting from the drilling operation. The location of the clamp is such to secure the maximum strength and rigidity.

For operating the solenoid 1 preferably provide a switch 33 conveniently located on the machine, as for instance on the saddle 5. This switch can be connected with the solenoid by means of a cable at the rear which is not shown. In Fig. 6 I have shown a diagram of the electrical connections Which may be used, though these connections are not claimed as a part of my present invention. The switch 33 includes two push buttons 34L and 35. When the button 34; is pressed, connection is made through contacts 36 and 37, thus directly connecting the solenoid 29 with the line. The solenoid acts to set the clamp in the way already described. The inward movement of the button 34: causes the button 35 to simultaneously move outward, thus establishing a connection between the contacts 38 and 39. By means of this connection a resistance ll) is placed in circuit with the solenoid 25). A lesser amount of current is required.- to hold the clamp in set position than required to initially set it. There is therefore provided a spring ll which serves to return the button 3% to its outer position'as soon as it is released by the operator. This breaks the main connection to the solenoid. The button 35, however, re mains: in its outer position, thus connecting the solenoid with the line through the resistance 40. The resistance 40 permits a current to pass which is just sufficient to hold the clamp in set position. When the operator desires to release the clamp he presses thereof as the arm and adapted to effect a.

direct. clamping engagement between the column and the base whereby the clamping is intensified in the vertical plane of the arm to directly resist the upward reaction of the arm during the drilling operation, and power means for operating the clamping device.

2. In a drilling machine, the combination of a base, a column rotatably supported on the base, an arm projecting horizontally from the column, drilling mechanism carried by the arm, a vertically acting clamping device carried by the column at the same side thereof as the arm and adapted to effect a direct clamping engagement between the column and the base whereby the clamping is intensified in the vertical plane of the arm to directly resist the upward reaction of the arm during the drilling operation, and a single cam operated means for effecting the clamping operation.

, 3. In a drillingmachine, the combination of a base, a column rotatably supported on the base, an arm projecting horizontally from the column, drilling mechanism carried by the arm, an operating motor carried by the arm support at the side of the column opposite the drilling mechanism, an antifriction column support at the axis of the column between the drilling mechanism and motor, and a clamping device carried by the column at the same side thereof as the arm and adapted to engage the base to effect a direct clamping engagement between the column and the base supplemental to the said support whereby the clamping is intensified in the vertical plane of the arm to directly resist the upward reaction of the arm during the drilling operation.

4. In a drilling machine, the combination of a base, a column rotatably supported on the base, an arm projecting horizontally from the column, drilling mechanism carried by the arm, a column support comprising a spring mechanism normally supporting the entire weight of the column, a vertically acting clamping device carried by the column at the same side thereof as the arm and adapted to effect a direct downward clamping engagement of the column with the base against the action of the spring mechanism whereby the colmun is chiefly carried directly by the base when the said clamping means is engaged and is carried entirely on the support by the spring mechanism when the said clamping means is disengaged.

5. In a drilling machine, the combination of a base, a column rotatably supported on the base, an arm projecting horizontally from the column, drilling mechanism carried by the arm, a horizontal annular flange on the base, a vertically acting clamping device carried by the column at the same side thereof as the arm and adapted to engage the annular flange and effect a direct clamping engagement between the column and the base whereby the clamping is intensified in the vertical plane of the arm to directly resist the upward reaction of the arm during the drilling operation, and power means for operating the clamping device.

6. In a drilling-machine the combination of a base, a vertically divided column mounted on the base for movement about a vertical axis, an arm vertically movable along the column between the parts thereof and projecting horizontally therefrom, drilling mechanism carried by the arm, a vertically acting clamp carried by the column at the same side thereof as the arm and adapted to effect a direct engagement be tween the column and the base, and operating mechanism for the clamp located between the parts of the column.

7. In a drilling machine, the combination of a base, a vertically divided column mounted on the base for movement about a vertical axis, an arm vertically movable along the column between the parts thereof and projecting horizontally therefrom, drilling mechanism carried by the arm, a horizontal annular flange on the base, a vertically acting clamp carried by the column at the same side thereof as'the arm and adapted to engage the annular flange and effect a direct engagement between the column and the base, and operating mechanism for the clamp located between the parts of the column.

8. In a drilling machine, the combination of a base, a vertically divided column mounted on the base for movementabout a vertical axis, an arm vertically movable along the column between the parts thereof and projecting horizontally therefrom, drilling mechanism carried by the arm, vertically acting'clamp carried by the column exteriorly and at the same side thereof as the arm and adapted to effect a direct clamping engagement between the. column and the base, and operating mechanism for the clamp including a solenoid located between the parts of the column.

9. In a drilling machine, the combination of abase, a vertically divided column mounted on the base for movement about a vertical axis, an arm vertically movable along the column between the parts thereof and projecting horizontally therefrom, drilling mechanism carried by the arm, a vertically acting clamp carried by the coluinn at the same side thereof as the arm and adapted to effect a direct clamping engagemcnt between the column and the base, the clamp including an eccentric carried by the column, and operating mechanism for the clamp including a solenoid located between the parts of the column and connected with the eccentric to turn it.

10. In a drilling machine, the combination of a base, a column rotatably supported on the base drilling mechanism carried by the column, an annular anti-friction column support at the axis of the column, a verti cally acting clamping device beneath the drilling mechanism and adapted to effect a direct clamping engagement betweenthe column and the base supplemental to the said support whereby the clamping is intensified in the vertical plane of the drilling mechanism to directly resist the upward reaction of the column and drilling mechanism during the drilling operation, the said column support and associated parts being constructed to leave an unobstructed central vertical aperture through the base and the lower part of the column adapted to receive a power shaft, and power means for operating the clamping device.

11. In a drilling machine, the combination of a base, a column rotatably supported. on the base, drilling mechanism carried by the column, a column support comprising a spring mechanism normally supporting the entire weight of the column, a vertically acting clamping device adapted to effect a, direct downward engagement of the column with the base against the action of the spring mechanism, whereby the column is chiefly carried directly by the base when the said clamping means is engaged and is carried entirely 011 the support by the spring mechanism when the said clamping means is disengaged, the said column support and, spring mechanism and associated parts being constructed to leave an unobstructed central vertical aperture through the base and the lower part of the column adapted to receive a power shaft.

12. in a drilling machine, the combination of a base, a column rotatably supported on the base, drilling mechanism carried by the column, an annular anti-friction column support, a vertically acting clamping device adapted to eitect a direct downward engagement of the column with the base, and a. centrally positioned vertically arranged coil spring between the support and the column acting vertically upward in opposition to the clamping means whereby the column is chiefly carried directly by the base when the said clamping means is en gaged and is carried entirely on the support by means of the spring when the said clamping means is disengaged, the said column support and spring mechanism and associated parts being constructed to effect a direct engagement between the column and the base, the said column support and associated parts being constructed to leave an unobstructed central vertical aperture through the coil spring and through the base and the lower part of the column adapted to receive a power shaft.

13. In a drilling machine, the combination of a base, column rotatably supported on the base, drilling mechanism carried by the column, an annular antifriction column support, a vertically acting clamping device adapted to effect a direct downward engage ment of the column with the base, a centrally positioned vertically arranged coil spring between the support and the column acting vertically upward in opposition to the clamping means, a central tube interposed between the spring and the column, and a central threaded bushing engaging the tube and the column and serving to adjust the pressure of the spring, the sevteral said parts being constructed to leave an unobstructed central vertical aperture through the base and the lower part of the column adapted to receive a power shaft.

1 1-. In a drilling machine, the combination of a base, a vertically divided column mounted on the base for movement about a vertical axis, an arm vertically movable along the column between the parts thereof and projecting horizontally therefrom, drilling mechanism carried by the arm, an annular anti-friction column support at the axis of the column, the said column support and associated parts being constructed to leave an unobstructed central vertical aperture through the base and the lower part of the column adapted to receive a power shaft,

a vertically acting clamp carried by the column at the same side thereof the arm and adapted to effect direct engagement between the column and the base, and operating mechanism for the clamp including a solenoid and a divided link, located between the parts of the column, the divided link leaving the central part of the column unobstructed to receive a shaft as before stated.

In testimony whereof, 1 hereto aiiix my signature.

lVlLLARD T. SEARS. 

